The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A transfer case for a 4×4 vehicle typically is capable of operating in two different gear ratios, often referred to as a high range and a low range. In general, shifting between the high range and the low range requires that the vehicle be stopped and that the vehicle transmission be shifted into neutral. Stopping the vehicle increases the chances of the vehicle getting stuck. Making a 4×4 range shift while the vehicle is moving can also help avoid a significant driveline torque disturbance when shifting the transfer case from neutral to high range or from neutral to low range caused by excessive transmission output shaft drag torque.
While systems for range shifting a transfer case are known in the art and achieve their intended purpose there still remains a need for improved systems and methods. More specifically, there is a need for a new and improved system allowing transfer case range shifting while the vehicle is moving while minimizing a change in propulsion, tractive effort, and/or driveline disturbance to the vehicle operator.